Air-motor.



M. CLARK.

AIR MOTOR."

APPLICATION FILED DEC. 16. I916.

1,230,995. PatentedJune 26, 1917.

2 SHEETS-SHEET l.

M. CLARK.

AIR MOTOR.

APPLICATION FILED DEC. 16. 1916.

Patented June 26, 1917.

2 SHEETS-SHEET 2- no. wAhHlNGrON, a c

UNITED TATE PATENT @FFKQE.

MELVILLE CLARK, OF CHICAGO, ILLINOIS, ASSIGNOR TO MELVILLE CLARK PIANO COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

AIR-MOTOR.

Application filed December 16, 1916.

To all whom it may concern:

Be it known that I, MELVILLE lLARn, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful lmprovements in Air-Motors, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to provide an improved construction of an air motor for operating the note-sheet propelling mechanism of an automatic piano player. It consists in the elements and features of construction shown and described as indicated in the claims.

In the drawings Figure 1 is a front elevation of a motor embodying this invention shown in connection with the train of mechanismby which it actuates the note-sheet propelling devices partly shown.

Fig. 2 is a fore-and-aft section through one of the motor pneumatics of the motor shown in Fig. 1.

Fig. 3 is a section at the line, 3-3, 011 Fig. 1.

Fig. 4 is a detail section at the line, 4-4, on Fig. 2.

The motor shown in the drawings comprises a partial vacuum chamber, 1, having connections by means of the pipe, 1*, with exhaust devices not shown. Upon one wall of this chamber there are mounted the motor pneumatics, 2, of which there are five in the motor as illustrated, each having its moving wall, 2 connected by a pitman, 3, with a crank, 4 of the main crank shaft, 4:, by which the motor operates the train by means of a chain, 5, driven by the sprocket wheel, 6, on said crank shaft. To cause the proper power-developing action of the motor pneumatics, each of them has a port of communication with the partial vacuum chamber through which the motor pneumatic is exhausted and collapsed, and also a port of communication with the atmosphere through which it is inflated. The first mentioned port, 7, leads directly through one wall 1 of the primary pneumatic or partial vacuum chamber, 1, and the fixed wall of the motor pneumatic mounted on said wall of the partial vacuum chamber. For affording the atmosphere communication with the motor pneumatic, a wall of the partialvacuum- Specification of Letters Patent.

Patented June 26, 1917.

Serial No. 137,437.

chamber adjacent to that having the port, 7 and, as illustrated, and most conveniently the upper wall, 1 of said partial vacuum chamber, is formed with ducts, 9, leading through it, one for each motor pneumatic, said ducts each communicating at one end by a port, 10, with the motor pneumatic served, and at the other end by a port, 10, with a duct, 11, formed in the wall 1, of the partial vacuum chamber opposite the wall 1 on which the motor pneumatics are mounted, each of said ducts, 11, leading from a valve chamber, 12, formed in said opposite wall, said valve chambers having their outer wall formed by a removable atmosphere port strip, 13, having for each of said valve cl1ambers an atmosphere port, 14:, which thus becomes the atmosphere port for the motor pneumatics situated at the opposite end of the duct, 9, in the top wall of the partial vacuum chamber. For controlling the exhaust port, 7 and the atmosphere port, 14, of the respective motor pneumatics, there are contained within the partial vacuum chamber two sets of primary pneumatics, one valve in each set pertaining to each primary pneumatic, said two valves hereinafter referred to as a pair, one set of primary pneumatics, 16, carrying valves, 17, for controlling the exhaust ports, 7, and the pneumatics, 18, of the other set carrying valves, 19, for controlling the atmosphere ports, 1.4:. The primary pneumatics of each pair are mounted on a duct bar, 20, supported in fixed position within the partial vacuum chamber and having ducts, 21, which com municate with the primary pneumatics carried by said duct bar, and by means of tubes, 22, which extend through the duct, 9, to reach the duct bar, 20, each having an atmosphere communication through a valve seat, 21, on top of the wall, 1 of the chamber. On said wall of the chamber there are mounted lever valves, 24 and 25, the valves, 24, controlling the ducts leading to the primary pneumatic, 16, and the valves, 25, controlling the ducts leading to the primary pneumatics, 18. These valves are conveniently shaped as illustrated so as to fulcrum at their middle points on top of the chamber, being pressed toward their seats by springs, 27, coiled around guide screws, 28, screwed into the top wall of the chamber, and the ends of said lever valves opposite the port-closing ends thereof, extend under a cam shaft, 30, which is journaled upon the upper end of the partial vacuum chamber, and rotated by a chain, 31, driven by sprocket wheels, 32 and 33, on the crank shaft and on said shaft, 30, respectively, so as to be revolved in uniform time relation with said crank shaft. On said shaft, 30, there are mounted cams, 35 and 36, for actuating the lever valves, 24 and 25, respectively, said cams being proportioned and positioned on the crank shaft and with respect to the lever valves which they actuate so that. each of said valves is held open throughout a little more than half of each revolution of the cam shaft, the two cams of each pair being oppositely positioned on the shaft so that, except for the short overlap of the open period of the two valves, one valve is open while the other valve is closed. It will be understood that the cranks are positioned on the crank shaft distributed at substantially equal angular intervals about the axis, which, with five motor pneumatics and cranks, yields the result that two of the motor pneumatics at a time are collapsing and giving to their respective pitmen proper thrust for rotating the shaft, while a third motor pneumatic is passing its collapsed position with its crank passing the center, so that it is substantially idle so far as its action on the shaft is concerned, and the other two motor pneumatics are being recovered from collapsed condition by the rotation of their respective cranks through the proper. portions of their arcs of travel for this purpose. And it will be understood that the cams on the cam shaft are positioned correspondingly to the cranks, so as to open the valves for connecting the motor pneumatics with the partial vacuum chamber to produce the collapse, and for opening the valves for admitting atmosphere to the motor pneumatics to permit their expansion, in proper time relation to the movements of the cranks in accordance with the thrust of the pitmen from the motor pneumatic upon the cranks, and of the cranks upon the motor pneumatics in the collapse and expansion of said motor pneumatics respectively.

It may be understood that the overlap of the open periods of the two valves for each motor pneumatic is provided in order that there shall not be at any time any partial vacuum operating in a motor pneumatic whose crank is in a position for expanding the pneumatic, and so that, on the other hand, the suction port and atmosphere port of the same motor pneumatic shall not be simultaneously open which would cause waste of the air by reduction of the partial vacuum without any work done thereby.

In the case of each of the atmosphere valves, 19, the stem, 19, which connects the valve to the primary pneumatic which actuates it extends loosely through the aperture,

1 in the wall of the valve chamber on the side toward the primary pneumatic chamber, so as to permit the stem to be rigid both with the primary pneumatic moving wall and with the valve, which rigidity causes the valve to be oblique to the valve chamber wall around the aperture, 1 and in order to prevent leakage around the stem when the atmosphere port is open there may be provided a thin flexible disk, 19, snugly carried on the valve stem but free by reason of its flexibility and thinness to wabble or take oblique positions on the stem, so that it will be sucked to a seating on the valve chamber wall around the aperture, 1 when the movement of the valve, 19, carries said disk, 19, against that wall. It will be understood that the primary pneumatics, 16 and 18, have the usual leak ports, 16 and 18, through which. they are exhausted to permit their collapse when their respective atmosphere communications are closed by the valves as described.

I claim z- 1. In an air motor, in combination with a.

tively the partial vacuum port and the atmosphere port of the motor pneumatics; a valve controlling the atmosphere communications of each primary pneumatic, and me chanical connections for operating said last mentioned valve by the crank shaft.

2. In an air motor, in combination with a crank shaft, motor pneumatics and connections by which they rotate the crank shaft; a partial vacuum chamber; primary pneumatics in said chamber, two 'for each motor pneumatic; the motor pneumatics having each a port of communication with the partial vacuum chamber and an atmosphere port; valves operatively connected respectively with the two primary pneumatics for each motor pneumatic, controlling respectively the partial vacuum port and the atmosphere port of the motor pneumatics; a valve controlling the atmosphere communications of each primary pneumatic; a cam shaft rotated by the crank shaft, and cams thereon operating said last-mentioned valves.

3. In an air motor, in combination with a crank shaft, motor pneumatics and con nections by which they rotate the crank shaft; a partial vacuum chamber; primary pneumatics in said chamber, two for each motor pneumatic; the motor pneumaticsv having each a port of communication with the partial vacuum chamber and an atmosphere port; valves operatively connected respectively with the two primary pneumatics for each motor pneumatic, controlling respectively the partial vacuum port and the atmosphere port of the motor pneumatics; a valve controlling the atmosphere communication of each primary pneumatic; a cam shaft rotated by the crank shaft, and cams thereon operating said last-mentioned valves, the cams for each pair of primary pneumatics pertaining to the respective motor pneumatics being positioned and proportioned for causing the open periods of the valves which they operate to overlap.

4:. In an air motor, in combination with a crank shaft, motor pneumatics and connections by which they rotate the crank shaft; a partial vacuum chamber; primary pneumatics in said chamber, two for each motor pneumatic; the motor pneumatics having each a port of communication with the partial vacuum chamber and an atmosphere port; valves operatively connected respectively With the two primary pneumatics for each motor pneumatic, controlling respectively the partial vacuum port and the atmosphere port of the motor pneumatic; a valve controlling the atmosphere communication of each primary pneumatic, and mechanical connections for operating said last mentioned valves by the crank shaft; the primary pneumatic chamber having in one wall ducts which communicate with the motor pneumatics respectively, and in an adjacent wall valve chambers having the atmosphere port for the respective motor pneumatics, and valves in said chamber controlling said ports and operatively connected respectively with the pneumatics of one set; said wall having also ducts from said valve chambers communicating with the ducts of the first mentioned wall, the wall opposite that which has said valve chambers having ports of communication with the motor pneumatics respectively, and valves operatively connected with the other set of primary pneumatics controlling said last mentioned ports.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 11th day of December, 1916.

MELVILLE CLARK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

